Electrical connector with printed circuit elements



W. D. NOVAK ELECTRICAL CONNECTOR WITH PRINTED CIRCUIT ELEMENTS Filed May 10, 1952 4 Sheets-Sheet l Inventor: War-Pen D. Novak, h m D M His Attornc eg.

W. D. NOVAK ELECTRICAL CONNECTOR WITH PRINTED CIRCUIT ELEMENTS Filed May 10, 1952 4 Sheets-Sheet 2 r o t n e v .m

Warren D. Novak 7%%mv%W- H is Attorngg.

Ap 1950 w. D, NOVAK 2,932,810

ELECTRICAL CONNECTOR WITH PRINTED CIRCUIT ELEMENTS Filed May 10, 1952 4 Sheets-Sheet 3 I/Ill Inventor: Wanren D. Novak,

|-|i$ Attorne s.

ELEMENTS W. D. NOVAK ;April 12, 1960 ELECTRICAL CONNECTOR WITH PRINTED CIRCUIT 4 Sheets-Sheet 4 Filed May 10, 1952 nK u :w Po n 0N w m flu A my .6 w H ELECTRICAL CONNECTOR WITH PRINTED CIRCUIT ELEMENTS Warren D. Novak, Liverpool, N.Y., assignor to General Electric Company, a corporation of New York pplication May 10, 1952, SerialNo. 287,208 8 Claims. (Cl. 339-17) This invention relates toelectrical connectors, and has as an object thereof to provide electrical. connecting means in which the electrical conductor elements thereof are of the printed circuit type.

Circuits are defined as being printed when they comprise conducting substances. secured to an insulating surface by any desired process. Printed circuits include electrical circuits which are stamped, stenciled, deposited, produced by etching processes, or otherwise applied to an insulating surface, regardless of the particular method of forming the conducting elements on the supporting surface.

It is also an object of the present invention to provide an improved electrical connector means. having a pair of separable members in which the contact pressure and the separation force between members are. independently controllable.

It is another object of the present invention to provide an improved electrical connector means including a pair of separable members constructed of interchangeable elements.

It is still another object of the present invention to provide an improved electrical connector means made of easily and economically formed and fabricated parts.

It is a further object of the present invention to provide an improved electrical connector o'ccupying a minimum of space.

It is still a further object of the present invention to provide an improved connector which is easily and readily serviced.

An additional object of this invention is to provide a quick detachable electrical connector having conductor elements applied to an insulating supporting surface in accordance with printed circuit. techniques and serving as a connector between two or more printed circuits, or between a printed circuit and a circuit of conventional wiring, or between two or more circuits of conventional wiring.

In carrying my invention into effect a pair of insulating members, each having printed on adjacent surfaces thereofa group of electrical conductors, is provided. The electrical conductors of the respective groups are maintained in desired electrical contact by pressure applied between the non-adjacent surfaces of the insulating members.

The features of this invention which I believe to be novel are set forth with particularity in the appended claims. My invention itself, however, both as to its organization and method of o'peration, together with further objects and advantages thereof, may best be understood by reference to the following description taken in connection with the accompanying drawing in which Fig. 1 is a view of an electrical connector assembly made in accordance with my invention; Fig. 2 is an exploded view of the connector assembly shown in Fig. 1; Fig. 3 is a detail view in section showing the manner of" connecting wires to the connector members of Figs. 1 and 2; Fig.

4 is a view ofa quick-detachable connector in which the printed circuit portions are completely covered when members of the connector are in a connected. position; Fig. 5 is a view of the clamp of Fig. 4 taken along section a-a thereof; Fig. 6 is a disassembled view of the two connector members of Fig. 4 showing their relationship to each other; Fig. 7 is a disassembled view of one of the connector members of the type shown in Figs. 4 and 6; Fig. 8 is an edge view of one of the connector members of the type sho'wn in Figs. 4 and 6 showing the manner of connecting 9 is an edge view of one of the connector members of the type shown in Figs. 4 and 6 after connecting conductors have been placed in position; Fig. 10 is an exploded view of a connector assembly showing the use of a connector member of the type shown in Figs. 4 and 6 connected to a panel member having printed circuit elements thereon; Fig. 11 is an endviewin partial section of the connector of Fig. 10 assembled; Fig. 12 is a view of a modified embodiment of my printed circuit connector used as a plug-in type connector; Fig. 13 is a disassembled view of the plug assembly of Fig. 12; Fig. 14 is a sectional view of the plug and receptacle members of the embodiment of Fig. 12; Fig. 15 shows another embodiment of my inventionyFig. 16 is a side View in section of the connector members of Fig. 15 disassembled; and Fig. 17 is a rear view of the receptacle member of the connector of Fig. 15.

Referring to Figs. 1 and 2 there is shown a connector assembly made in accordance with my invention in which insulating wafer members, having conducting elements positioned thereon in accordance with printed circuit techniques, connect together groups of conventionalwires. The conductors of wire groups 1 and 2, each shown as having ten conductor members, are connected to conducting elements 5 positioned on insulating wafers 3 and 4, respectively. The insulating wafer members 3 and 4 may comprise any suitable insulating material, such as a hardened phenolic resin, on which the conductor elements 5 have been previously applied in accordance with any of the various printed circuit techniques. The printed conducting elements 5 are positioned on the upper surface of wafer member 3 and on the lower surface of wafer member 4 with respect to the view shown in the drawing so that when wafers 3 and 4 are placed together with conducting elements of respective wafers 3 and 4 arranged in conductive registration, the conductors of wire group 1 will be connected to the conductors of wire group 2 through the printed elements on the respective Wafers 3 and 4.

Any number of pairs of wafers may bestacked together in this way to furnish electrical connection between groups of wires. Two additional wafers 6 and 7 are shown with wire groups 9 and 10 attached thereto and with the printed elements on the respective wafer members connecting the two wire groups together. The assembled stack of wafer members may be held together in any suitable manner and in the embodiment shown in the drawing a pair of metal button members 11 and 12 hold the wafer members together as will be hereinafter de scribed.

Referring now particularly to Fig. 2 there is shown at the uppermost portion of the figure wafer member 4 having a plurality of conducting elements 5. It will be noted that the conducting elements 5 are positioned on the under surface of water member 4 and that the conducting elements extend parallel to one another from one of the edges of the wafer, in this case the left-hand edge, for approximately one-half the Width of the wafer, after which each element diverges from the parallel relationship into conductive connection with one of the terminals 8, the under surfaces of which are shown in the drawing.

Conducting elements 5 are. similarly positioned. on wafer conductors to the connector member; Fig.

members 3, 6 and 7. For more compact designs, particularly in miniature applications, it may be desirable to use a method of termination which permits the elements to be parallel throughout their lengths. Preferably, the ends of the printed circuit elements should not extend to the edge of the wafer and should be rounded to avoid sharp corners which might cause voltage breakdown, particularly at high altitudes.

It will be noted that each mating wafer member overlaps its companion wafer member only with respect to the portion of the wafer member on which the conducting elements are arranged in parallel relation, so that each wafer member projects beyond the other wafer by a dis- .tance amounting to approximately one-half of the width of the respective wafers. The wafer portions which are not overlapped contain the terminals for the respective wire groups. 7

While I have shown in the embodiments of Figs. 1 and 2 the use of only four wafers which form two mating pairs of waters, any desired even number of wafers may be stacked in assembled relation. For example, ten, twelve, or more wafers may be stacked in assembled relation.

The wafers may be held together by any suitable compression device, and in the embodiment illustrated in Figs. 1 and 2, I have shown the use of a pair of metal button members, each of which has an internally threaded cap member 11 and a screw member 12 which pass through apertures 13 in each of the wafers and screw together to hold the wafers in assembled relation. In order to prevent bowing of the wafers due to the elevated conducting elements on the wafers when they are clamped together in this way pairs of conductive members 11' elevated above the surface of respective wafer members to the same extent that conductive elements 5 are elevated are formed on each wafer on the sides of the holes 13 opposite from sides on which conducting elements are located.

There is shown in Fig. 3 a sectional view, partially cut away, of the end of an insulating wafer member and of a terminal attached to the wafer member showing the way in which wire conductor members may be attached to wafer members of the type shown in Figs. 1 and 2. A hole is provided through the wafer member perpendicularly to the plane thereof at a point slightly inwardly of its outer edge and a metal eyelet 14 is expanded in the aperture in such manner that the outer flange portions 15 of the eyelet are compressed against the opposite outer surfaces of the wafer member. The bare end 16 of the conductor member is then positioned interiorly of the 'eyelet 14 and a slug or portion of solder 17 is used to fill the space between the outer surface of the conductor and the inner surface of the eyelet. The eyelet and terminal are so positioned on the wafer that one of the conducting elements 5 will extend into conducting relation with the conductor, solder, and eyelet.

Applicant'has thus provided a connector in which a large number of wafers may be stacked with good electrical contact between conductive elements, yet be easy to detach.

There is shown in Fig. 4 an embodiment of my invention in which each member of the pair of wafer members supporting the conducting elements is so constructed that when a pair of the wafers are placed in contacting relation with respect to one another, the conducting elements are substantially sealed from exposure to the atmosphere and are additionally arranged for quick assembly and disassembly. The connector members can be separated with ease yet when assembled good contact is maintained between conductive elements. In this figure a pair of wafer assemblies 18 and 19 are connected to wire groups 20 and 21 respectively. Wafer assemblies 18 and 19 are basically similar to the wafer members previously describedin connection with the embodiment of Figs. 1, 2

I and 3 and differ principally in the structural arrangement of the wafer assemblies and in the manner of connecting two wafer assemblies the conducting wires to the printed circuit elements of the wafer assemblies.

As can best be seen in Fig. 6, each of the wafer assemblies 18 and 19 comprises a base portion on which conducting elements are positioned and laminated strip members 22 and 23 attached to the terminal ends of the base portions of assemblies 18 and 19 respectively. Laminated strips 22 and 23 serve to seal'the portions of the respective wafer assemblies which are not lapped with respect to each other, thereby helping to make the connector members weatherproof. The laminar stripportions 22 and 23 are substantially of the same thickness as the base portions of the respective wafer assemblies upon which the printed circuit elements are positioned. When the 18 and 19 are placed in assembled relation with respect to each other and with respective conducting elements in registration, the superposed laminar strip member of one of the wafer assemblies will be coplanar with the base portion of the other wafer assembly.

It will be noted that in the embodiment of Figs. 4 and 6, the respective wafer assemblies are wider at the end at which the wire groups are connected than at the end containing the parallel portions of the conducting elements. At the end of the respective wafer assemblies where the conducting wires are connected, the conducting elements diverge from their parallel relation and this necessitates that the wafer assembly be wider at this end. While in the embodiment of Figs. l-3, the respective wafer members are of the same width at the terminal end of the wafer member and at the end where the conducting elements are parallel, in the embodiment of Figs. 4, 5 and 6, the width of the respective main body portions containing the parallel conducting elements has been reduced in order to accommodate a suitable spring clamp member 24 which holds the plurality of wafer members in assembled relation. The conducting elements of the wafer members may also be parallel throughout the length thereof and it is this type which are used in the embodiment shown in Figs. 15, 16, 17 as will be more apparent below.

In Fig. 4 and Fig. 5 are shown views of clamp member 24. The frame of the clamp member 24 is of generally U-shaped construction and has a bottom portion positioned under the bottom surface of wafer assembly 18, with respect to the view shown in the drawing, and two upright arm portions 25 and 26, which are substantially perpendicular to the bottom portion. The two superposed wafer assemblies 18 and 19 are slid in between the upright arms 25 and 26 of the clamp, with the outer surface of wafer assembly 18' resting on the inside bottom surface of the clamp. A leaf spring member 27, which may be made of some suitable material such as beryllium copper, extends longitudinally ofthe clamp and is supported at each of its opposite ends by a projecting portion 28 which extends into an aperture in each of the respective upright portions 25 and 26 of the clamp. The spring member is bent into a curve having 5?. axis parallel to the longitudinal direction of the spring. The bottom of the curved portion of the spring is lower than the two outside longitudinally-extending edges of the spring by an amount of the order of .030 inch. The bottom surface of the spring 27 rests on the outer surface of water assembly 19, with respect to the 29 and 30, each having a thumb pressure member, extend longitudinally between and are pivotally supported by the two upright end members 25 and 26. Each .of the respective buckle lever members 29 and 30 is provided with a longitudinally extending edge at substantially right angles to the plane of the thumb portions. The buckle lever members may be rotated down into their closed position, as shown in Fig. 4, by rotating the respective buckle levers about their respective longitudinal Two buckle lever membersaxes: When this is done, the right-angle edge of each of the buckle lever members will exert a pressure against the spring member 27 and force the center of the spring 27 into good contact with the surface of the wafer assemblies. Pressure of the spring 27 against the superposed portions of wafer assemblies 18 and 19 causes the mating printed circuit elements on the respective Wafers to be pressed together with considerable force. As a result, the contact resistance between the mating conductor elements is reduced to a neglible value. Line contact permits the spring to exert even pressure even though the thickness of the wafer members is slightly non-uniform.

There is shown in Fig. 7 an exploded view of a wafer assembly 31 similar to the wafer assemblies 18 and 19 of Figs. 4 and 6. The wafer assembly 31 comprises a base portion 32 on which the conducting elements are contained and a strip member 33 which is laminated to one end of the base portion 32. 'It will be observed that the left-hand end of the base portion 32, which con tains the parallel sections of the conducting elements, is not as wide as the right-hand end which contains the divergent sections of the conducting elements to which the terminal members are connected. The strip member 33 which is normally laminated in superposed relation to the terminal end of the base portion 32 is shown detached from the base portion 32. The strip member 33 is provided with a plurality of slots or round holes 34 which are in registry with the respective conducting elements of base portion 32. Strip member 33 is further provided with a plurality of holes 35 as can best be seen from Fig. 8 which extend from the terminal edge of the strip member 33 to respective slots 34.

After strip member 33 is laminated to base portion 32, a conducting wire 36 is then inserted in each of .the holes 35, as can best be seen in Figs. 8 and 9, the inner end of the wire 36 projecting into slot 34 for part of the length of slot 34. A small slug or portion of solder is then placed in each of the slots 34. The slugs of solder may be heated by an iron-tipped soldering iron so that the soldering iron does not wet and draw the solder, or by means of a carbon pencil with sufiicient current passed therethrough to melt the solder and make a good joint, or the solder may be melted in induction heating apparatus. In this manner, the wires 36 are firmly attached in conductive relation with the printed circuit elements on base portion 32.

Connector members constructed in accordance with the embodiments of Figs. 49 have been found to be particularly strong and durable. When strain is placed upon the wire conductor members attached to the solder slugs of the connector member, the solder slugs are capable of withstanding a large amount of strain. No strain is put upon the printed circuit elements when the wires are pulled, despite the fact that the wires are electrically connected to the printed conducting elements.

of 175 pounds was obtained before all ten wires broke.

In this case not a single terminal connection for any of the wires failedf There is shown in Fig. an illustration of the manher in which insulating wafer connector elements having printed circuit conducting elements thereon in accordance with my invention may be used to make electrical.

connection between a group of wires and a utilization device having printed circuit conducting elements. This is in contrast to the arrangements of Figs. 1-9 in which the printed circuit connector elements of the invention are used to connect together groups of wire conductors. A connector member 37 similar to those hereinbefore described having printed circuit conductor elements on its under surface, which are connected to a wire group 38, is provided. In the illustration there is shown the use of a wafer assembly similar to those shown in Figs. 4-9, inclusive, in which a strip member is laminated to the terminal end of the wafer assembly. However, it will be understood that the connector device illustrated in Fig. 10 couldjust as Well have a wafer member similar to those shown in Figs. 1-3, inclusive, in which the laminar strip member is not used.

A panel member 39 which may be part of a radio or other electronic equipment, for example, is shown a plurality of printed circuit conducting elements 40 positioned on its upper surface. The various conducting elements 40 are conductively connected to various components of the electrical equipment of which panel 39 is a part. The panel 39 is provided with a projecting portion 41 which conforms substantially to the shape of the portion of wafer assembly 37 on which the parallel portions of the conducting elements are positioned. The printed circuit conducting elements 40 extend on to projection 41, where they are positioned substantially parallel to each other so as to conform to the arrangement. of the corresponding conducting elements on wafer assembly 37. The wafer assembly 37 is then placed with its surface having the printed circuit elements in abutting relation to the surface of projecting member 41 on which the conducting elements 40 are positioned, in such manner that the respective conducting elements of each of the members will be in registration with the corresponding elements of the other member. A clamp member such as clamp 24 shown in Fig. 4 or any other suitable clamping means, may be used to hold the respective connector members together.

A spring strip member 42 having a base portion 43 and end tabs 44 is provided to maintain clamp 24 integral with panel 39. To achieve this result clamp 24 is placed in position with the base portion thereof flush with the upper surface of the base portion43 of member 42 and the combination slid into place in panel 39 in such a way that the end tabs 44 lock into position in the slot recesses 45 of the panel member. The member 37 is then placed in abutting relationship to member 41 through clamp 24 and is locked in place by closing tabs 29 and 30. To release member 37 tabs 29 and 3t! are opened and member 37 is withdrawn without causing the entire assembly to come apart. To move clamp 24 from the locked position with respect to panel 39 it is merely necessary to bring pressure against one of the tabs 44 by means of a pointed instrument until the tab 44 moves down and out of the slot 45 at which time members 42 and 24 spring free of panel 39. In Fig. 11 is shown an end view in partial section of the assembled arrangement of Fig. 10. As is apparent from an inspection of Figure 1.1, the holes 35 in the strip member 33 may actually comprise grooves in the face of member 33 adjacent the base member 32.

An important feature of all of the embodiments of the invention discussed thus far and shown in Figs. 1-11, inclusive, is that in all of these embodiments the printed circuit conductor elements may be assembled with high contact pressure and yet have low separation forces. This is in contrast to conventional multiconductor plugs in which the two prime requisites of a good electrical connector,.high contact pressure and low separation force, are mutually dependent with one requisite being met at the expense of the other requisite. For example, in the conventional multiconductor connector, as the number of conductors is increased, the contact pressure between male and female elements must be reduced or the total separa- -7 tion force of the complete assembly becomes excessive and intolerable.

With a connector constructed in accordance with the embodiments of Figs. 1-9, the contact pressure and the separation force are completely independent of each other. Contact pressure is the same amount on every conductor and it can be as high as the insulating base for the printed elements, such as a phenolic resin board or sheet, will stand without cracking. With even the most simple type of cam or screw it is possible to obtain contact pressures many hundreds of times greater than those available in any of the spring-finger type contacts of conventional connectors. Since the compression device is entirely released when the connector is disassembled, the separation force in connector members in accordance with my invention is substantially negligible.

In the embodiments of Figs. 1-9 the connector members are interchangeable due to identical unit construction.

In Figs. 12, 13 and 14 there is shown a hermetically sealed plug-in type connector employing printed circuit connector members. In Fig. 12 is shown a male plug assembly indicated generally at 46 and a female receptacle indicated generally at 47. The plug assembly 46 is connected to a wire group 48 and the receptacle 47 is connected to a wire group 49. The plug assembly 46 in the embodiment comprises two individual wafer assemblies similar to those shown in Figs. 4 and 6 having their respective base portions positioned in a back-to-back relationship with respect to each other. Thus, as it can be seen in Figs. 13 and 14, plug assembly 46 comprises an upper wafer assembly 50 having a base portion on which printed circuit conducting elements are positioned facing upwardly with respect to the view shown in the drawing, and a similar wafer 51 having a base portion on which printed circuit conducting elements facing downwardly with respect to the view shown in Fig. 13 are positioned. A spacer 52 of suitable insulating material, such as molded synthetic rubber or similar resilient plastic, is interposed between the respective wafers 50 and 51 and extends for a distance less than the length of the wafer assemblies 50 and 51 leaving a space for insertion of pressure means as will be hereinafter described. The assemblies 50 and 51 are encased in a suitable housing 53. The housing 53 may be made of a resilient plastic material such as rubber or the like and is molded with holes for the insulated conductors. Insulated wires are drawn through the holes in the housing and are soldered into place on the assemblies 50 and 51. The rubber housing is then drawn up in position until it surrounds and holds the assemblies 50 and 51.

The receptacle 47 comprises a pair of wafer assemblies 54 and 55 similar to the wafer assemblies 50 and 51 and each having a base portion on which conducting elements. are positioned with a laminated strip member 7 at the terminal end of each base portion. The wafer assembles 54 and 55 are positioned with respect to each other in such a manner that their respective laminar strip members are in face-to-face relation and the printed circuit surfaces of the respective base portions are also in face-t'o-face relation but displacedfr'om each other by a suitable insulating spacer 56, for example Textolite;

'The assemblies 54 and 55 are encased in a suitable housing 57 which maintains the, assemblies in proper spaced relationship. In the side walls of the housing 57 are located apertures 58. A spring member 59 having a pair of oppositely curved bow members fastened along a common longitudinal edge thereof with the other longitudinal edges free is held in place between assemblies 54 and 55 by taps on spring member 59 extending into the apertures 58. Accordingly, when the assembly 46 is inserted into the assembly 47, the spring member 59 fitting between the members 50 and 51 of plug assembly 46 holds the respective conductive elements of assemblies 50 and 51 in good conductive contact with the respective conductive elements of assemblies 54 and 55. Wire groups 48 and 49 are connected to wafer assemblies 50, 51 and 54, 55, respectively. Each of the respective wafer assemblies 50, 51 and 54, 55 has a strip member laminated at the terminal end thereof and respective conducting wires are connected to each wafer assembly in the same manner as previously described in connection with the embodiments of Figs. 4 through 9, inclusive. However, in assemblies 54 and 55 conducting tubes 60, made of copper for example, are first soldered in place and then the conducting wires are inserted therein and soldered in place. The end of the assembly 47 including conducting tubes 60 is sealed with an epoxy resin, or other suitable material to hermetically seal the end of the assembly 47. The housing 57 of assembly 47 may have a flange portion 61 which may be soldered or brazed to panel member 62. The housing 53 of assembly 46 is also made of a synthetic rubber or plastic material so that when assembly 46 is plugged into assembly 47 a substantially splash-proof connection may be obtained. 7

Referring now to Figs. 15, 16 and 17 there is shown a still further embodiment of my invention showing a compact and rugged connector. This connector includes a plug member and a receptacle member having respective wire groups 65 and 66 attached thereto. As can best be seen in Fig. 16, the plug member 63 comprises a pair of assemblies 67 and 68 each including a base portion on which conducting elements are positioned with a laminated strip member at the terminal end of each of the base portions. Wafer assemblies 67 and 68 are positioned with respect to each other in such a manner that the respective laminar strip members are in face-to-face relationship and the printed circuit surfaces of the respective base portions are also in face-to-face relationship and displaced from each other spacer 69 of Textolite, for example. Wafer assemblies 67 and 68 are encased in a housing 70 which includes boss portions 71 which register with the grooves in the assembly members 67 and 68 to hold the assemblies securely in the housing 70.

The receptacle member 64 comprises a pair of assemblies 72 and 73 similar to the wafer assemblies of plug 63, each including a base portion on which conducting elements are positioned with a laminated strip member at the terminal end of each of the base portions. Wafer assemblies 72 and 73 are positioned with respect to each other in such a manner that their respective'laminar strip members are in opposed relationship and the printed circuit surfaces of the respective base portions are on the remote faces of the assemblies 72 and 73. Spacer member 74 having longitudinal keys on opposite faces thereof which register with corresponding grooves on the assembly members 72 and 73 keys the latter in place. The spacer member 74 extends flush with the lateral ends of the assemblies 72 and 73 so that when the assemblies are inserted in housing 75, the forward edge of the spacer 74 abuts against the rear edge of the boss members 74' on the sides of housing 75 and prevents assemblies from extending further into the housing. The assemblies are further secured in place by tabs 76 on the housing 75 which are peened over to prevent the assemblies 72 and 73 from moving rearward. A suitable resilient element 78, for example, silicone rubber slab, is inserted between the assembly members 72 and 73 and may be cemented to either of the latter members so that when the plug 63 is inserted into the receptacle 64, the

bosses 77 on the upper and lower surfaces of the housing 75 cause the resilient element 78 to exert pressure on the assemblies 67, 68, 72 and 73 to produce a good electrical contact therebetween. The resilient element extends just short of the lateral edges of members 72 and 73 so that the boss members 74 slides in between members 72 and 73. A detent 79 is formed on tab member 80 fastened to the forward end of housing 75. Do:

by an insulating it tent 79 catches the rear edge of plug housing 70 when members 63 and 64 are in a mated position to lock the latter members in place.

Wire groups 65 and 65 are attached to the plug 63 and receptacle 64, respectively, in a manner similar to the manner shown in connection with Figs. 4 through 9.

Fig. 17 represents a rear view of the receptacle 64 of Fig. 16 showing the manner in which elements of receptacle 64 are fastened together.

While I have shown in Figs. l2-l7 a plug-in and receptacle members in which two wafer assemblies are placed in back-to-back relation and mate with two wafer assemblies in a face-to-face relation, it is obvious that a single wafer assembly could be employed in each of the plug and receptacle members.

Connector members having printed circuit conducting elements positioned on insulating wafers as hereinbefore described have many advantages over multi-conductor connectors of the type heretofore used. Connector members in accordance with my invention virtually eliminate the necessity of any machine tool work in connection with the manufacture of the connector members. A further advantage is the fact that these connector members are much smaller for a given number of conductors than previous types of multi-conductor connectors. A multi-conductor connector assembly can be built up utilizing a plurality of wafer members in order to connect several hundred or more conductor members to their mating conductors and in an overall volume which is considerably less than that of multi-conductor connector members heretofore used.

An idea of the compact size of connector which can be built in accordance with my invention is shown by the dimensions of plug members which I have already constructed. For example, I have built a basic wafer assembly such as is shown at 18 or 19 in Figs. 4 and 6 which is about 1% inches in width, 1 inch in depth, and about ,1 inch in thickness. Within these dimensions I have been able to place 10 conductors for a 10 circuit plug.

Also, I have built a connector of the plug-in type shown in Figs. 1214 which is of the order of inch high, 1 /2 inches deep and 1% inches wide for a twenty conductor male and female plug.

Further, I have built a connector of the type shown in Figs. 15-17 which is of the order of 1 inches by 1%. inches by inch for a twenty conductor male and female connector.

Still further, I have built a connector of the type shown in Fig. 15 which is of the order of one-half inch by onehalf inch by one-eighth of an inch for a twenty conductor male and female plug. Smaller size connectors can be made limited, only by the size of the insulated wire to which it is connected.

Furthermore, it should be noted that each connector assembly is built up of a plurality of identical wafer elements. Thus, the use of connector members in accordance with my invention eliminates the need for having diifering male and female connector members in accordance with the practice hereinbefore used in constructing electrical connector members. Connector members in accordance with my invention offer the advantage of complete interchangeability, and a single basic element can be made the nucleus from which are formed both male and female parts in connector assemblies whose capacity ranges from ten conductors to several hundred or more conductors.

A further advantage of connector members in accordance with my invention is the fact that repairs are more easily made to my connector members than in the case of conventional multi-conductor connectors. Thus, a broken terminal or a section of burned installation need not be the cause for discarding the entire connector assembly, as would often be the case with conventional 10 multi-conductor connector assemblies, but only the particular wafer aifected by the damage need be replaced. I

A still further advantage of my connector device is the fact that repair and wiring changes can be easily made. Regardless of how many conductors are collected together in a connector of the type in accordance un'th my invention, the operator is never forced to work on a repair or wiring change in a wiring area any more congested than that of a single wafer.

A still further advantage of connector members in accordance with my invention is the fact that the connector members may be easily cleaned. This is particularly true of the embodiments of my invention shown in Figs ll1. When the compression device, such as the: screw buttons shown in Figs. 1 and 2, or the clamp shown in Fig. 4, is released, all of the wafers may be withdrawn and the full area of the electrical contacting surfaces is immediately exposed, thereby permitting them to be thoroughly cleaned or polished. The conducting surface of the printed conductor elements may be completely renewed without disconnecting any of the conducting wires. For example, where copper is the base metal of which the printed conducting elements are formed, the plating may be renewed by making the metal surface of the printed conductors chemically clean and then replating without disassembly of wafer.

Connector plugs having the un-laminated strip member of Figs. 13 have proven very satisfactory under varying conditions of humidity. This type of plug construction has been tested up to 150 hours in humidity test varying from 35 percent to percent relative humidity in cycles. After hours, the connector plug was removed and within 5 minutes a check of insulation resistance between adjacent terminals throughout all ten elements were made. The average insulation resistance between adjacent conductors was of the order of 50 megohms after 150 hours exposure to humidity. Under normal room conditions of temperature and humidity, insulation resistance in the order of two to three hundred thousand megohms between adjacent conductors is experienced. Contact resistance from one plug element to the plug element with which it mates is of the order of one-hundredth of an ohm, either in normal room temperature and humidity conditions or after long exposure to high humidity conditions.

A number of high-voltage break-down tests have been conducted on connectors having printed circuit elements in accordance with my invention. In connectors where the spacing between the parallel portions of adjacent conductor elements is I inch, a break-down voltage of between two and three thousand volts has been attained at sea level pressure conditions. Voltage breakdowns of the order of 500 volts have been experienced at a simulated altitude of 80,000 feet. In connector designs where the spacing between adjacent conductor elements has been increased to inch, the breakdown at sea level conditions remains in the range two to three thousand volts, but the voltage breakdown at simulated altitude conditions of 80,000 feet is increased to the order of 700 volts between adjacent conductors.

More than 3600 push-together tests with mated con nector members of the type shown in Fig. 15 were made without a single failure in continuity. This same design of connector having a plug with twenty conductors and a corresponding mated receptacle with twenty conductors was subjected to push-together tests with more than 12,500 cycles of pushing the mated members completely into one another with no evidence of tearing up of the printed circuit conductors from the insulating base and no evidence of excessive wear on any conductive elements.

It can be seen that I have provided a new and improved electrical connector member which is compact and permits the attachment of a substantially greater number of conductor elements for a given volume than electrical connectors in accordance with the prior art. Furthermore, electrical connector members in accordance with my invention have many other advantages, as hereinbefore described, including simplicity of manufacture and ease of disassembly for repair or replacement.

While I have shown and described particular embodiments of my invention, it will be obvious to those skilled in the art that various changes and modifications can be made therein without departing from the invent-ion and I, therefore, contemplate by the appended claims to cover all such changes and modifications as fall within the true spirit and scope of my invention. I

What I claim as new and desire to secure by Letters Patent of the United States is:

1. Electrical apparatus comprising an insulating panel member having a plurality of conductor elements of the printed type thereon, the ends of said conductor elements being disposed in one region of said panel member, a plurality of electrical conductors, an insulating wafer member having a plurality of printed circuit conducting elements on a surface thereof, each of said conductors connected to respective printed circuit conducting elements on said insulating wafer member, said surface of said wafer member being disposed in face-to-face abutting relation with respect to said region of said panel member, each of said conductor elements on said panel member being in conductive contact with respective conducting elements of said wafer member, alignment clamp ing means exerting a force normal to said surfaces for holding said wafer member and said region of said panel member in aligned assembled relation with respect to' each other, whereby the conducting elements of said wafer member are maintained in good conductive relation with corresponding conductor elements of said panel member.

2. An electrical connector member comprising a pair of insulating wafer base portions each having thereon a plurality of printed circuit conducting elements, the conducting elements of each of said base portions extending adjacent to one edge of respective base portions, insulating strip members laminated to respective base portions adjacent said edge thereof and overlying the termini of said conducting elements, said strip members being provided with a plurality of slots, a separate one of said slots overlying each of said printed circuit conductor elements, a plurality of conducting wires each aligned with respective conducting elements andeach overlapping in said slots respective conducting elements, a portion of solder lying in each of said slots and conductively uniting each of said conductor elements with respective conductin-g wires, the faces of said base portions including said conducting elementsbeing in face-to-face abutting relation to each other, whereby the conducting elements on one of said base portions make electrical contact with corresponding conducting elements on the other of said base portions.

3. An electrical member comprising a pair of insulating wafer base portions each having thereon a plurality of printed circuit conducting elements, the conducting elements of each of said base portions extending adjacent to one edge of respective base portions, an insulating strip member laminated to each of said respective base portions adjacent said edge thereof and overlying the termini of said conducting elements, said strip members being provided with a plurality of slots, a separate one of said slots overlying each of said printed circuit conducting elements, and each of said strip members having a plurality of apertures in substantial-alignment with respective ones of said slots, a plurality of conducting wires each inserted in respective apertures to an extent which will place said respective wires in communication with the respective slots, a portion of solder lying in eachof said slots and conductively'uniting the respective printed circuit conductor element and wire conductor corresponding to each of said slots, the respective base portions of each of said wafer assemblies on which said conducting elements are positioned being in face-to-face abutting relation to each other, whereby conducting elements on one of said base portions are in electrical contact with corresponding conducting elements on the other of said base portions.

4. An electrical connector comprising first and second insulating base members, each of said base members having a plurality of substantially parallel conductive strip elements printed on a face thereof, a plurality of conductors, each of said conductors being aligned with and in overlapping conductive relationship with respective ones of said conductive elements, first and second insulating strip members positioned in abutting relation to the face of the respective base members, said insulating strip members having apertures in registry with regions of overlapping conductive contact, solder means in said apertures for fastening said overlapping conducting pairs together, whereby good conductive contact and high resistance to separation between said conductors and said conducting elements is obtained, and means for holding said base members in slidably engageable face-to-face relation.

5. An electrical connector comprising a plug and a receptacle therefor, said plug and receptacle each including a pair of insulating base members, a plurality of substantially parallel conducting elements printed on the proximate faces of said plug base members, a plurality of conductive elements printed on the remote faces of said receptacle base members, means including a resilient spacer of insulating material for maintaining the respective ones'of each of said pairs of base members in substantially parallel spaced relation and means for holding said plug and receptacle conducting elements respectively in slidably engageable relation with one another, said holding means including means for clamping said resilient spacer under pressure intermediate said base members when engaged, whereby said plug and receptacle conducting elements are maintained in good conductive contact.

6. An electrical connector comprising a plug and a receptacle therefor, said plug and receptacle each including a pair of wafer assemblies, each of said wafer assemblies comprising an insulating base member having a plurality of substantially parallel conducting elements printed on a face thereof, a plurality of conductors, each of said conductors being aligned With'and in' overlapping conductive relationship with respective ones of said conductive elements, an insulating strip member having apertures in registry with regions of overlapping conductive contact, solder means in said aperture for fastening said overlapping conducting pairs together, whereby good conductive contact and high resistance to separation between said conductive and said conducting elements is'obtained.

7. An electrical connector comprising in combination first and second base members made of electrically insulating material, a plurality of straight parallel electrically conductive elements printed on at least one face of each of said base members, a first strip member made of insulating material and mounted in abutting relation to said first base member so as to cover only a portion of said first base member, means defining apertures in said first strip member that are in registrywith the conducting elements in said first base member whereby solder placed in said apertures is prevented from flowing to adjacent conductive elements and whereby the solder so placed provides mechanical resistance to the pulling out of electrical conductors that may be inserted between said firstbase member and said first strip member and electrically connected to said conducting elements by the solder, a second strip member made of insulating material and mounted in abutting relation to said second base member so as to cover only a portion of said second base member whereby solder placed in said apertures is prevented from flowing to adjacent conductive elements and whereby the solder so placed provides mechanical resistance to the pulling out of electrical conductors that may be inserted between said second base member and said second strip member and electrically connected to said conducting elements by the solder, means defining apertures in said second strip member that are in registry with the conducting elements printed on said second base member, and means for clamping said base members and said strip members together in such manner that the corresponding conducting elements printed on said first and second base members are in contact.

8. An electrical connector as set forth in claim 7 wherein the adjacent surfaces of said strip members are grooved so as to provide convenient access for electrical conductors to the conducting elements.

References Cited in the file of this patent UNITED STATES PATENTS Eisler May 25, 1948 Del Camp Aug. 15, 1950 Earle et a1 July 10, 1951 Lavender Sept. 4, 1951 Kovach Aug. 28, 1951 Cox June 17, 1952 Brunetti Sept. 16, 1952 Del Camp Oct. 7, 1952 Kamm May 29, 1956 FOREIGN PATENTS Great Britain Sept. 10, 1931 

